Dental instrument.



L. T. CANFIELD.

DENTAL INSTRUMENT.

APPLICATION FILED MAR. 10. 191-6.

1,1851%? Patented June 20,1916.

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LINNAEUS '1. GARFIELD, 0F TOLEDO, OHIO.

DENTAL INSTRUMENT.

specification of Letters Patent. Pfijgnted J n 2Q, 3915,

Application filed March 10, 1916. Serial No. 83,224.

To all whom it ma concern:

in the art to which it appertains to make and use the same, reference being had to the accompanying drawings, and to the letters and figures of reference marked thereon, which form a part of this specification.

In the practice of dentistry, the delicate operations of removing nerves and of exploring and treating nerve-canals are rendered difiicult for the operator, as well as painful to the patient, owing to the many difi'erent positions which such an instrument must assume, and to the irregular and ofttimes obscure course of the channel to be followed.

My invention relates to an instrument designed to largely. obviate the difiiculties here indicated, and, more particularly, is designed to provide an instrument which,

while furnishing a rigid shaft, providing an ample handle for the firm hold of the operators fingers, is still so delicately flexible near its forward end as to yield to the slightest change of position of the handle or to the course of the pliant broach removably held at the extreme end of the instrument in the grip of a suitable chuck.

To these ends, my device consists of the construction and arrangement of parts hereinafter described,'and shown, and illustrated in the accompanying drawings, in which-- 7 Figure 1, is a side-elevation of my instrument in normal position; Fig. 2, the same, showing the connection between the handle and the chuck hereinafter referred to, flexed, the dotted lines indicating, approximately, the range of the instruments deflection, and Fig. 3, an enlarged view, in central longitudinal section, of my device.

Like numerals of reference indicate like views throughout the drawings.

In the drawings, 1 is a stem or handle,

preferably corrugated longitudinally, to afford a holdlng surface for the fingers of the operator.

2 is a closely coiled fine wire helix, the

opening at one end of which receives and is secured upon the reduced portion 3 of the handle 1. The other end of the helix recelves and is secured upon the inner end of a chuck 4 which may be of any suitable conw struction. In the present instance, for illustration, the chuck consists of a cylindrical piece of steel 5, split lengthwise into four equal segments, the splits extending from.

the blunt point formed by its conical end to 16 near the encircling helix, thus forming prongs 6. The conical quadripartite nose of the cleft piece 5 is threaded to receive the nut 7. The prongs 6 are resilient. The butt of the broach 8, which is usually of about the;

diameter of a fine sewing needle, being inserted into the socket between the endsof the prongs 6, and the nut 7 being set up, the ends of the prongs are compressed inwardly and the end of the broach is tightly clamped in operative relation to the -han-" dle. Now the turning of the handle will cause a like turning of the broach. It will be seen that owing to the flexibility of the connection between the handle and the broach, as well as to the flexibility of the broach itself, the'broach may be effectively turned and manipulated throughout an arc of nearly one hundred and eighty degrees. The operator is thus enabled to reach with:- ease the root or nerve canal of every tooth in the mouth. 'Another advantage of the construction here described is that since the short resilient helix shown forms the sole connection be tween the handle and the chuck, the helix while capable of holding the chuck and handle normally in alinement not only permits the deflection above described but being slightly extensible and compressible, serves"' What I claim and desire to secure by Letthehandle, said helix forming the sole conters Patent, is-- nection between the handle and the chuck. 10

A dental instrument comprising, in com- In testimony whereof I' aflix my signature bination,"a handle, a chuck having compresin presence'of two witnesses. 6 sible arms adapted to clamp a broach, a com; LINNAEUS T. CANFIELD.

pression-nut for compressing said arms, and Witnesses: a wire helix forming sockets at each end for GERTRUDE BRAGKER,

receiving the opposed ends of the chuck and J. H. JAMEBON. 

